One of the difficulties with online shopping experiences is that they are virtual. You cannot go into a store and see, touch, and smell what you are trying to buy before you buy it. For some types of products, such as clothing and food, this virtual factor can be a strong impediment to the shopping experience. In addition, you must wait for a purchased item to be delivered—it isn't immediately available for your consumption or use.
On the other extreme, if you are willing to transport yourself to a store or other similar venue (e.g., a fair, open market, discount warehouse, and the like), you can see, touch, and smell what you are trying to buy and obtain it immediately. However, the inconvenience may be substantial. You may need to visit several stores which may be located some distance apart to find the exact item you are looking for. Further, in some geographic areas, stores with certain types of products may not be available at all.
In addition, from the supplier's standpoint, small businesses with limited real-estate and other limited resources may be at a disadvantage in traditional storefront shopping models. They may not be able to carry a large array of inventory or have the footprint to easily display it. They may not be able to afford targeted marketing campaigns or prices to compete with bigger companies. Thus, the mega-warehouses and discount facilities have an advantage when it comes to simply pushing large amounts and types of product at potential consumers.
Also, in both the online virtual and traditional physical shopping scenarios, it can be difficult to obtain a “try-before-you-buy” purchase experience. Some products and suppliers are amenable to this, but a majority are not, especially in the online or virtual shopping scenario. At most, you can purchase something and then return it, sometimes with a “money back guarantee.” Some vendors even offer to pay return postage and pick up the merchandise to be returned the consumer still must arrange it.
Vending machines offer yet another type of point of purchase physical shopping opportunity. The vending machine is pre-stocked typically with a certain class of goods (e.g., drinks from a single vendor or distributor) or with goods of a pre-defined form factor and/or limited selection. Vending machines are typically located for convenience to purchasers, such as in other retail locations, hotels, businesses, transportation facilities, and the like. Returns are not really viable—you might be able to negotiate with the business at the location (e.g., building, hotel, store, event location, etc.) that hosts the vending machine, but you cannot return the good to the vending machine itself. There is no advertising of new products available—it is a “get what you see, when you see” sort of system.